报告人：杨伟国 副教授()

主持人：郑玉峰 教授

时  间：1月16日（周三）下午 15:00

地  点：工学院力1号楼210会议室

Abstract:

Surface topography have been reported to play a key role in modulating cell behaviors, yet the mechanism has not fully understood especially on three-dimensional (3D) topographies. In this study, a series of novel TiO₂ hemispherical 3D imprints ranging from nanoscale to microscale were prepared on titanium (Ti) surfaces by using a customized interfacial nanosphere lithography method. Mouse embryo osteoblast precursor cells (MC3T3-E1) were selected to investigate the solitary effect of specific 3D hemispherical imprints on cellular behaviors. The results indicated that varied 3D hemispherical imprints can affect the formation of filopodia and the arrangement of cytoskeleton differently, thereby altering the spreading morphologies of cells and leading to deformation of the nucleus, which eventually affects cell proliferation and osteogenic differentiation. The cells cultured on different 3D hemispherical imprints exhibited promoted proliferation and osteogenic differentiation at different degrees, among which cells cultured on hemispherical imprints with 90 nm 500 nm formed abundant filopodia and exhibited the highest ALP activity and osteogenic related gene expression level, respectively. A 4-week of ectopic implantation also confirmed an improved osteogenic ability in vivo of 90 nm hemispherical imprints compared with unpattern Ti substrate. Together with a promoted proliferation, colonizing more cells on the surface of implants and inducing rapid osteogenic differentiation can be achieved simultaneously. To conclude, our work has provided a rational approach to study how material surface topography determines the fate of bone cells, thereby improving the quality of bone-implant integration. 

Speaker’s Bio:

     Dr. Yeung is currently tenured associate professor in the Department of Orthopaedics and Traumatology, The University of Hong Kong. His major research areas cover from the development of orthopaedic biomaterials, 3D bio-printing as well as musculoskeletal tissue engineering.  He trained as materials scientist in his bachelor degree and then orthopaedic scientist in HKU Medical Faculty for his master degree and PhD, respectively. He.  His h-index is 43 with more than 5,900 citations.  In addition to his more than 200 peer-reviewed SCI journal papers published and 38 filed full patents in various countries, he has also co-founded the OrthoSmart Limited together with two senior professors so as to translate their research findings to clinical use. During these years, he had received numbers of award and scholarship from local and regional competitions such as Young Scientist Award 2005 and Young Engineer Award 2009, respectively. The total amount of grants and sponsors directly arising from his projects in PI and Co-PI capacity is over HK$67M.  Additionally, he has supervised 8 PhD and 11 MPhil students since 2006. Furthermore, he obtained 18 prizes and awards from local and international competitions and conferences.